1. Related Technical Field
Related technical fields include systems, methods, and programs for generating an electronic map database suitable for use in a navigation systems.
2. Related Art
Japanese Patent Application Publication No. 2003-195747 (pages 5-6 and 10-11, FIG. 3, and FIG. 17) describes a system for generating an electronic map database. The structure of this system is shown in FIG. 15. A map data generating device 101 formed by installing a predetermined program on a general-purpose computer constitutes the nucleus of the system. On the basis of a road database 102 defined by links constituted by line segments and nodes serving as intersection points between the links, and an aerial photograph 103, attribute information is set in relation to each of the links in the road database 102. Thus, a new map database is generated. Here, attribute information is information regarding the structure and traffic regulations of each link.
The map data generating device 101 includes a command input portion 104, a database referencing portion 105, a polygon generating portion 106, a pattern database 107, a pattern analysis portion 108, an attribute setting portion 109, and a result output portion 110. The command input portion 104 inputs a command from an operator. The database referencing portion 105 references the road database 102 and the aerial photograph 103 on the basis of the input command. The polygon generating portion 106 generates a closed figure from each of the links defined in the road database 102 (to be referred to hereafter as a polygon) having a predetermined surface area. The pattern database 107 stores various image patterns included in the aerial photograph 103 in association with corresponding attributes.
For example, the pattern database 107 stores an association between the “parking lot” attribute and a pattern such as that found in a parking lot, in which short line segments forming a vehicle parking space are disposed at fixed intervals, or an association between the “no passing” attribute and a yellow line such as a center line. The pattern analysis portion 108 reads the aerial photograph 103 and analyzes the image patterns included therein on the basis of the pattern database 107. The attribute setting portion 109 sets attribute information in relation to the links in the road database 102 on the basis of an analysis result of the pattern analysis portion 108. The result output portion 110 receives a setting result from the attribute setting portion 109, associates the attribute information with each link, and outputs a new map database.